The present invention is directed to a microsensor device for measuring or regulating at least one of chlorine and bromine ions. More particularly, the invention is directed to a thick film electrochemical microsensor capable of measuring or regulating the level of chlorine and bromine ions in swimming pool or spa water. The invention further encompasses a method of measuring or regulating the levels of chlorine and bromine ions in swimming pool or spa water using the electrochemical microsensor.
In order to insure that the water in a pool or spa is safe, it must be properly sanitized to prevent any health problems arising due to algae, bacteria, or any other pathogens which may be in the water. Currently, chlorine and bromine are commonly used to sanitize pools or spas. The chlorine comes in a number of different forms: sodium hypochlorite (liquid bleach), calcium hypochlorite, lithium hypochlorite or chlorinated isocyanurates. When any of these materials interact with water, they undergo hydrolysis to form free chlorine consisting of predominantly hypochlorous acid (HOCl), which is the sanitizing agent, and hypochlorite ion. Free available chlorine (FAC) is the amount of unused or unreacted chlorine. Combined available chlorine (CAC), also known as chloramines, is the portion of chlorine which has interacted and combined with contaminants. For the purposes of this invention, measurement of chlorine refers to the chlorine ion Clxe2x88x921, as well as hypochlorous acid HOCl, and hypochlorite ion OClxe2x88x921.
The National Spa and Pool Institute recommends 1 to 3 parts per million of free chlorine in the water and a pH between 8 and 10. Most pool or spa owners use a visual test which measures the amount of total chlorine in the water, not the amount of free available chlorine. This visual test can be incorrectly performed or inaccurately interpreted, and the wrong amount of chlorine may then be added to the water. This inaccuracy often leads to an unwanted chlorine odor, red, burning eyes, or the spread of diseases among the swimmers.
Electrochemical sensors have been used in various fields because of their cost effective mode of operation and uncomplicated method of manufacture. U.S. Pat. No. 5,676,820 to Wang et al. describes a sensor used to monitor metal contaminants in a remote location, connected via a communications cable to an analysis device. Microsensors have also been used to detect acidity in water, as well as to monitor species such as carbon dioxide and hydrogen sulfide.
It is therefore an object of the present invention to provide a thick film electrochemical microsensor for measuring or regulating at least one of chlorine and bromine in water such as swimming pool and spa water.
The present invention provides an electrochemical microsensor device for measuring or regulating ions of at least one of chlorine and bromine comprising, a substrate supporting an arrangement of at least two electrodes, wherein one of the electrodes is an anode and one of the electrodes is a cathode, wherein the electrodes are formed or fabricated using a thick film technique, and wherein the anode is adapted for oxidation of chlorine and bromine ions.
The present invention further provides a method of measuring or regulating ions of at least one of chlorine and bromine in water comprising contacting the water with the electrochemical microsensor device of the invention, measuring the current output of the sensor, determining the level of chlorine and bromine indicated by the current output, and generating a signal.
It has been found that chlorine and bromine can be measured in water using a thick film electrochemical microsensor device. Novel electrode configurations were designed and tested, and the results are reported herein, along with a preferred electrode configuration.
Advantageously, the thick film electrochemical microsensor device of the present invention can be used to actuate a regulating means to maintain an appropriate level of chlorine and/or bromine in swimming pool or spa water.